The first stuffed, sealed, continuous business form assembly that allowed easy extraction of contents that were printed while within the envelope is disclosed is commonly assigned (U.S. Pat. No. 3,104,799 issued to D. J. Steidinger on Sept. 24, 1963. The advent of the Steidinger form created a whole new field of business forms that were particularly well suited for large scale mailings of individualized information.
Because business forms of this sort have been so successful, a large number of variations on the basic form devised by Steidinger have been proposed. One such proposal is contained in commonly assigned U.S. Pat. No. 4,747,535 issued May 31, 1988 to Haase et al. The structure disclosed in the Haase et al patent relates specifically to a so-called "two-way" envelope, although the principles of the same are not limited to such envelopes. In that construction, part of the original envelope is removed by the recipient to expose a flap which may then be folded over the remainder of the original envelope to provide a return envelope. A unique means of opening the Haase et al envelope and/or free insert material within the pocket of the envelope are features of the Haase et al invention.
The structure of the Haase et al invention works well generally for its intended purpose. However, part of the means defining a tear strip for achieving access to the contents of the original envelope do not operate as postively as might be desired. In addition, the means by which removal of the tear strip free the contents of the original envelope requires great care in manufacture or else such means may not operate with the high degree of reliability that is desired in forms of this type.
The present invention is directed to overcoming one or more of the above problems and, even more broadly, to provide a) improved tear strips, and b) easily releasable, adherance of two or more ply receipts together in continuous business forms.